Wireless telegraphy



July 20,1926. 1,593,269

' H. J. ROUND WIRELESS TELEGRAPH! Filed March 30 1922 H. J. ROUND,

3% f"? 9 fiww Patented July 20, 1926,

ITED S'l'rt'l'fifi PATENT QFHCE.

HENRY JOSEPH ROUND, OF LONDON, ENGLAND, ASSIGNOR TO RADIO CGIBPOIRA'IION OF AMERICA, A CORPORATION OF DELAl/VARE.

WIRELESS TELEGBAPI-IY.

Application filed March 30, 1922, Serial No. 548,004, and in Great Britain April 7, 1921.

This intention relates to improvements in wireless telegraph and telephone systems.

According to this invention I provide a By the use of such aerials short waves can be transmitted and retransmitted over a long d1 stance.

It is known that the current induced in a vertical aerial of an effective height 71 by a current in. another vertical aerial of an effective height 71. at a distance a3 bears to the inducing current the ratio 377 hi k? 'y (ZR where y is the wave length and R is the resistance of the receiving aerial, when the distance between the aerials is such that attenuation can be neglected.

If therefore there be a pair of nearly vertical aerialseach tuned to a wave length not much greater than the fundamental wave length, and by means of a valve set with retroaction on, say, the second of these aerials the resistance be reduced to a very low value, almost equal currents can he obtained in each aerial by the induction from a supply into the first aerial alone; for instance, with two aerials each 20 metres'high working at a wave length 100 metres with the aerials reduced to ohm effective resistance by retroaction the currents in the two will be equals about 3 kilometres, and the distance can be increased if the resistance be still further diminished.

The second aerial will in turn induce a current back into the: first one which will again in turn react on the second aerial.

So that if we now apply (1) If the current in the second aerial. is es than in the first and'the two aerial retauces are reduced to the same figure. then,

the current in the second aerial will induce back still less in the first aerial, and so on, the final currents being the sum of where e is less than 1.

(2) If, however, the current induced in the second aerial be larger than in the first aerial, then obviously the whole system will react up to an oscillation limit; in other words, the slightest induction in either aerial will produce this maximum current, that is to say, the system will start itself oscillating.

e are concerned here with the case where is finite and the system is not self oscillatory but will respond proportionally to any induced E. M. F.

If either aerial be now altered in damping, the current in the other one will be affected, more or less proportionally. As a result it is possible over short distances to bridge a gap between the telephone wire systems. This is illustrated in the accompanying diagram, in which A A, are aerials coupled through any suitable rectificrs R R to the telephone lines T T for example, by means of antenna coupling coils B B and transformers C C The aerials A A are provided with valve sets V by which their resistance is reduced. 'The valve sets may comprise for example, three electrode tube feed back or retroaction circuits, in which grid coils D D are coupled to coils B E and feed back coils E connected to the plate and plate battery are coupled. to B B or D 1),. An oscillator O of any kind is arranged to produce oscillations of the transmitting frequency in one of the valve sets.

When speech arrives at T the voltage applied to the rectifier R varies the damping of the aerial system A, owing to the fact that m e or less of he H- en g in the lis chopped off and absorbed in the resistance IV, depending on the voltage impressed by the speech curre ts "from the line T This modulates the current in the aerial, conse quently the current in A, is also reduced and the value of the current rectified by It, and transferred to the line at T is modulated according; to the speech modulations. Similar) any speech arriving at T will supply modulated current to the line at 'i thus giving a two-way system of telephony on the same wave lei h. Also for telegraphv an oscillator may he provided at each station and modulation produced by malringand breaking. It is obvious that it we arrange a or group of such stations A A A with an oscillator at one of them only, each of thenican at once spcaltto any other of the set or group-provided the whole systen is stable and does not burst into oscillations automatically. I do not limit myself to this simple system o't modulation which has been given by way of illustra tion as any other method of varying damping'or phase can be used for the purpose of modulation. I

Instead of setting upagroup of such stations I can arrange a chain of them (A A A5) across country. At any placein the system I can then. induce an E. M. F. in resonance with the system and at that place or any other place I can modulate the resulting currents as I have above described in the case of only two aerials.

Having described my invention, what I claim is: I

1. The combination of two telephone wire systems having a gapv and means for brides in'g'the {sap comprising apair of aerials atthe ends of the gap, each being arranged to receive waves from the other, and each having: means associated therewith for causing magnification and re-radiation of waves received from theother.

In radio signalling systems, a pair of aerials ataconsiderable distance apart, and eachof said aerials being arranged to receive waves from each other and having associated therewith means tor reducing its apparent resistance to such a value with re spect to the aerial spacingthat currents in one aerialinduce currents of substantially equal value in the other. v

3. In radio signalling"system's, a pair or spaced aerials, an oscillator at one of said aerials and retroactive means at the otheraerial for ainplifyingithe received currents Vofthe oscillator frequency said serials b einfr'so'sp'aced that the'currents in the second aerial. may be amplifiedto substantial equality with the currents of the first aerial. I p

4;; In, radio signalling systei 1s,' pair of spaced aerials,*a'n oscillator at oneof said serials, retroactive means cooperating with each of said aerials and said aerials being so spaced that the retroactive means substantially equalizes currents of the oscillator frequency in said aerials.

5. In radio signalling apparatus, a plurality ct aerials, each of said aerials being arranged to receive waves from each other and having associated therewith means for causing magnification and re-radiation of waves received thereon from any other of said aerials, and at least one of said aerihaving an oscillator associated therewith.

6. In radio signalling apparatus, a plurality of acrials, each of said aerials being arranged to receive waves from each other and having associated therewith means for causing; magnification and re-rad'iation of waves received thereon from any other of said aerials, and at least oneof said aerials havingassociated therewith means for modulating the currents therein.

7. In radio signalling apparatus, a plurality o1" aerials, each ofsaid aerials being arranged to receive waves from each other and having; associated therewith means for causing magnification and re-radiation of waves received thereon from any other of said aerials, and at least one of said aerials having associated therewith means for modulating the currents therein at speech frequencies.

8. In radio signalling systems, a plurality of aerials forming an extended chain, each of said aerials being arranged to re ceive waves from each other and having as sociated therewith means for causing magnification and re-radiation of waves received thereon from any other of said aorials, and at least one of said aerials having associated therewith means for modulating currents therein.

9. In radio signalling systems, a plurality of aerials forminr an extended chain, each of said serials being arranged to receive waves fromeach other and having associated therewith means for causing magnification and r'e-radiation of waves received therein from any other ot' said aerials. least one of said aerials having associated therewith means for modulating currents therein, and at least one of said acrials having an oscillator associated therewith; p y 4 p 10. radio signalling; system comprising a pluralityof aeria' ls, each havingretroac tive means associated therewith and tuned to the same wave length, said aerials and said retroactive means beingso arranged and adjusted as to cause each aerial to receive, magnify and re-radiate' waves from and to each other and to substantially equalize the currents in each.

11. A radio signalling" system comprising a plurality of serials, each having retroao tive means associated therewith and tuned to the same Wave length, said aerials and said retroactive means being so arranged and adjusted as to cause each aerial to receive, magnify and re-radiate Waves from each other and to substantially equalize the currents in each, and an oscillator associated with one of said aerials and arranged to generate oscillations of a predetermined frequency.

12. A radio signalling system comprising a plurality of aerials, each having retroactive means associated therewith and tuned to the same wave length, said aerials and said retroactive means being so arranged and adjusted as to cause each aerial to receive, magnify and re-radiate waves from and to each other and to substantially equalize the currents in each, and means for modulating the currents of the system.

13. In radio signalling apparatus a pair of spaced aerials, means for reducing the apparent resistance of each of said aerials to cause substantial re-radiation of received Waves thereby and said aerials being so spaced that the reradiated Waves from each Will cause cumulative efiects in the other.

14. In radio signalling apparatus a pair of spaced aerials, means for reducing the apparent resistance of each of said aerials to cause substantial reradiation of received Waves thereby and said aerials being so spaced that the reradiated Waves from each will be received by the other to successively increase the current in each.

HENRY JOSEPH ROUND. 

